public void checkValid(CharSequence literal) throws DatatypeException {
// TODO Find out if it is safe to put this in a field
IRIFactory fac = new IRIFactory();
fac.shouldViolation(true, false);
fac.securityViolation(true, false);
fac.dnsViolation(true, false);
fac.mintingViolation(false, false);
fac.useSpecificationIRI(true);
fac.useSchemeSpecificRules("http", true);
fac.useSchemeSpecificRules("https", true);
fac.useSchemeSpecificRules("ftp", true);